Complete volume with articles 1 to 32 - Cucurbit Breeding - North ...

Genetic Variability in Ascorbic Acid and Carotenoids Content in Indian Bitter Gourd
(Momordica charantia L.) Germplasm
S.S.Dey, T.K.Behera and Charanjeet Kaur
Indian Agricultural Research Institute, New Delhi-110012, India. Email:tusar@rediffmail.com
Bitter gourd (Momordica charantia L.) is one
of the important vegetables among the
cultivated cucurbits. The crop is widely
cultivated through out the tropics. The origin
of this important crop is probably India with a
secondary centre of diversity in China (2).
India is endowed with a wide range of
diversity in this crop; hence, there is a vast
opportunity for genetic improvement. The
immature fruits are good source of iron,
vitamin A, B, C, and inexpensive source of
proteins and minerals (7) and the nutritive
values of bitter gourd fruits vary with the
varieties. The small-fruited (Momordica
charantia var. muricata) types are found to be
more nutritious than the large-fruited
(Momordica charantia var. charantia) types
(6). The systematic evaluation of bitter gourd
genotypes based on ascorbic acid and
carotenoids content in bitter gourd is either
lacking or scanty. Therefore, a study was
made to evaluate bitter gourd germplasm with
high ascorbic acid and total carotenoids
content besides several other traits.
A total of thirty eight accessions of bitter
gourd collected and maintained at the
Division of Vegetable Science, Indian
Agricultural Research Institute, New Delhi
were grown in a randomized block design
with three replications during March to July
2004. The recommended agronomic practices
were adopted for optimum growth of the crop.
Most of the economically important fruit and
plant characters were also observed during the
cropping period. The predominant sex form
was monoecious; however, two very
promising gynoecious lines and two
predominantly female flowering types were
included in this study. Number of fruits per
plant varied from 7.07 to 47.07 and weighted
from 10.47g to 136.41g each. Fruit length
ranged from 3.26 cm to 28.72 cm with
diameter from 2.55 cm to 5.98 cm and flesh
thickness of 0.31 cm to 2.08 cm. The color of
the fruit was from milky white to dark green.
Fruit surface also showed different
conformations i.e. continuously ridged to
almost smooth. For analysis of ascorbic acid
and carotenoids, fruits were picked at
commercial edible stage. Ascorbic acid was
determined by titrating a known weight of
sample with 2,6-dichlorophenol-indophenol
dye using metaphosphoric acid as stabilizing
agent (1). Total carotenoids were determined
by a modified method of one described by
Ranganna (5).
Data were averaged and statistically analysed.
The analysis of variance indicated highly
significant differences among the genotypes
for ascorbic acid and carotenoid content. This
suggests that there is a considerable amount
of variation among the genotypes. Mean,
range, phenotypic (PCV) and genotypic
(GCV) coefficient of variation is presented in
Table 1. The variability estimate revealed that
the phenotypic coefficient of variation (PCV)
was higher than the genotypic coefficient of
variation (GCV) for all quantitative characters
studied but the difference between PCV and
GCV for ascorbic acid and total carotenoid
content was insignificant which indicated that
these quality traits are least affected by
environment. The above findings were in
agreement with the results obtained by
Jaiswal et.al. (3). The range of ascorbic acid
content was 60.20 mg to 122.07 mg/100 g of
fresh weight with a population mean of
82.14mg/100g of fresh weight (Fig. 1).
Similarly, total carotenoid content ranged
from 0.205mg to 3.2mg with a population
mean of 1.6mg/100g of fresh weight (Fig. 2).
The highest amount of ascorbic acid was
found in genotype DBTG-3 (122.07mg)
followed by DBTG-8 (120.53mg), DBTG-6
Cucurbit Genetics Cooperative Report 28-29: 91-93 (2005-2006) 91